Article drying apparatus



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ARTICLE DRYING APPARATUS Filed April 9, 1941 4 Sheets-Sheet 1 Broma@ Wv'lfsow,

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Feb. 16, 1943. B. WILSON ARTICLE DRYING AFPARATUS Filed April 9, 1941 4 Sheets-Sheet 3 CNTACT Wl H SUUDS.'

Fb. 16, 1943. B, wlLSON 2,311,148

ARTICLE DRYING APPARATUS Filed April 9, 1941 4 Sheets-Sheet 4 CONT ACI WHH SULIDS.

Patented Feb. 16, 1943 ouai ou nUUIIl UNITED STATES PATENT OFFICE 8 Claims.

The present invention relates to a drying apparatus and more particularly to a device or apparatus for the cleansing and drying of vegetables, fruits or other articles and simultaneously for the cleansing and drying of the mops, towels or other wiping devices employed in wiping and drying of the said articles.

The device of the present invention is particularly designed for the drying of potatoes after they have been subjected to a cleaning operation, but it will be understood that the invention may be applied to the drying of produce or articles of substantially any form having superficial or adhering moisture thereon which is to be removed therefrom.

In the drying of fruits, vegetables or other articles by the methods heretofore used, it has been customary to employ towels or cloths for the removal of surface water, but the cleaning and drying of the towels has presented a problem, and the towels or mops have generally been separately dried by the passage thereof through Wringers, or by means of fans by blasts of air. This drying operation has been difficult to control, and it has been found that either too much moisture is left in the mops or towels thus causing insufficient drying in the subsequent use, or, less frequently. too much moisture has been removed from the towels or mops so that they do not immediately operate satisfa-ctorily in taking up moisture from the surface of the article to be dried.

Itis well known that a dry cloth, chamois, and the like does not absorb moisture readily until it has become thoroughly wet, but that after it has been thoroughly soaked and the excess water removed or squeezed out, it takes up water or moisture substantially immediately in coming into contact with water or a moistened surface. This action takes place obviously by means of capillary attraction, or capillarity in the same manner substantially that a wick draws up liquid when in cont ct with water or other liquid.

It has beer found that if moisture is removed from a cloth so that in addition to the removal of the free moisture held between the interstices of the warp and weft threads, a portion of the moisture held between the bres in the strands of the cloth is also removed, the cloth may still remove moisture with avidity, provided that the amount of moisture left is suicient to retain a high degree of capillarity so that the cloth may be readily wetted again.

It will be understood, of course, that the amount of moisture which should be removed from the strands or cloth employed in .the drying operation, so as to retain the greatest effectiveness in the removal of moisture, varies with the nature of the material, the weave, the composition of the bres, the amount of natural oil or grease in the fabric, the temperature of operation and other factors. In the use of any particular material, therefore, it is preferable to make a trial run on the material under the temperature conditions of operation to determine the absorption capacity of the material and the minimum moisture content at which the material retains its maximum capillarity, or in other words, the point at which the material begins to lose its avidity or capacity for readily taking up moisture by capillary attraction. 'I'he rate at which moisture may be removed by the material from the produce may also be determined, by which the number of wiping units, the speed of travel, and the other necessary factors may be determined in connection with the treatment of the specific articles to be dried.

It is essential that the drying of the mops, towels or other wiping units be provided for in large scale drying operations, which heretofore has presented the main difliculty in continuous operation for the removal of water or moisture from articles to be dried.

The device of the present invention is designed to overcome drying diiiculties in connection with large scale operation and comprises briefly an apparatus having a series of mops or towels suspended upon cross rods so as to move over the produce or article to be dried in a direction opposite to that of the produce, the mops or towels being dragged over the surface of the articles to produce a wiping motion, by which water is drawn from the surface of the articles onto the mops or towels by capillary action. The rods on which the mops are suspended are Preferably mounted on chains which are driven on supporting sprockets and arranged so as to guide the towels or mops in a cycle, which includes first passing the drying units over the produce, then under spray nozzles and thence through wringers and from thence into a chamber in which provision is made for greatly reducing the speed of passage of the drying units through the chamber and crowding them together so that air for drying the units passes intimately into contact with the towels or mops to produce drying, and finally the drying units pass out of the chamber into engagement again with the produce to be dried. In passing through the drying chamber in which there is delayed action in passage therethrough,

the rods may be passed over an inclined track as hereinafter described in connection with the preferred form of the invention illustrated in Fig. 1 of the drawings, or they may be passed onto a second pair of endless chains or conveyor belts as illustrated in the modification hereinafter described in which the drying units move at a much slower rate of speed than the conveyor chains or belts which operate to drag the mops or towels over the surface of the articles to be dried. The mops or towels to be dried are moved at such a rate of speed along the drying chains or drying circuit as to supply the towels at the desired intervals to the main link belt or mopcarrying chains so as to produce continuity of operation of the apparatus. An air stream or air current, heated to a proper temperature, is passed through the apparatus so as to substantially remove the remaining moisture from the produce after the removal of moisture by the mops or towels, and the air is then utilized to thoroughly dry the mops or towels ln transit across the short circuit over the main mop-rod carrying chains, or through the towel-drying zone of the apparatus.

The produce to be dried is passed through the apparatus on one or more conveyor belts, being passed through the entire length of the apparatus in the drying operation.

As illustrated in a modified form of the invention, a series of conveyor belts may be used and in this form the produce after passing across the rst conveyor belt is dropped onto the next conveyor belt lower in the series, and after the produce passes across the apparatus on each belt, it is finally discharged from the apparatus.

One of the objects of the invention is to provide a form of apparatus adapted for the eflicient drying of potatoes or the produce in a continuous drying operation in which the wiping devices produce a preliminary drying of the produce after which it is further dried by means of air and the wiping devices are simultaneously dried in a cycle of operations without interference with the continuity of the operation by which the produce is dried.

Another object of the invention is to provide a form of apparatus which is adapted for use in connection with a continuous process for the drying of potatoes or other produce, in which means are provided for the separate cleansing and drying of the wiping devices and in which the movement of the wiping devices during the drying operation is controlled in proportion to, or in accordance with, the speed of travel of the produce through the drying apparatus, so that the wiping units will be cleansed and dried and be in readiness for the wiping of additional produce as it is passed on the conveyor belts into contact with the dried wiping units.

Another object of the invention is to provide a form of apparatus for the drying of produce with the concurrent, rapid cleansing and drying of the mops or wiping devices at elevated temperatures so as to provide the desired degree of dryness and to provide substantially the maximum capillary action for the removal of moisture from the produce.

Another object of the invention is to provide a form of apparatus for the drying of mops or wiping units in a compartment separate from that in which the produce is dried, and in which the wiping units are dried at an elevated temperature having reduced speed of travel, the rate of speed being delayed by bringing the wiping devices closely together or substantially in contact laterally so as to create resistance to the passage of air through and between the wiping units, thereby providing a controlled rapid drying thereof.

Another object of the invention is to provide a form of apparatus for the treatment or drying of produce which is highly ellcient in operation and which may be carried out at a low cost per unit weight of the produce treated.

'Ihe various features of the invention are illustrated in the accompanying drawings showing a preferred form of the apparatus and a modifica.- tion thereof, in which:

Fig, 1 is a sectional view in elevation showing the preferred form of the drying apparatus of my invention;

Fig. 2 is a sectional view in elevation taken substantially on the section line 2-2 of Fig. 1, but with the main parts of the apparatus of Fig. 1 omittedy to show the flue for combustion gases and a heat exchanger in connection therewith;

Fig. 3 is a sectional plan view of the heat exchanger taken on the section line 3 3 of Fig. 2;

Fig. 4 is a sectional view in elevation of a modified form of the drying apparatus of my invention;

Fig. 5 is a detailed view of a portion of the apparatus taken on the section line 5-5 of Fig. 4 in the direction of the arrows;

Fig. 6 is a detailed view partly in section taken on the section line 6 6 of Fig. 4 in the direction of the arrows;

Fig. 7 is a detailed view showing a mop or wiping unit and mounting therefor;

Fig. 8 is a detailed view showing a portion of a link belt with the notch therein for engagement with the mop rod together with one track on which the corresponding mop rod roller rides; and

Fig. 9 is a sectional view taken on the section line 9--9 of Fig. 8.

Figure 10 is an enlarged fragmentary vertical section taken along the line I 0|0 of Fig. 5.

Referring now to Fig. 1 of the drawings illustrating the drying apparatus of my invention in its preferred form, the apparatus comprises a chamber 2 in which is an endless conveyor 4 adapted for receiving and conveying the articles to be dried, the conveyor being mounted in any suitable manner, as on sprockets B and 8, which are rotated in a clockwise direction so that the upper portion of the conveyor belt moves to the right in the direction of the arrows 5. The conveyor belt is preferably made up of sections of three rollers 3, 5 and 1, the forward end of the section being pivoted on the conveyor chain as indicated in the left of Fig. 1.

The articles or the produce to be dried may be fed onto the conveyor from an inclined chute or opening 22 which may be so inclined that the articles are gradually fed onto the conveyor. The articles are then carried to the right through the entire length of the chamber 2, and in order to assist in drying the articles during the said passage, a series of wiping units or mops 40 are drawn slowly over Athe surface of the articles in a direction opposite to that in which the articles are transported on the conveyor. During this passage of the wiping units the main portion of the moisture on the surface of the articles is removed by the capillary action of the cloth or strands of the wiping units, which become progressively more moist in their passage to the left through the chamber 2.

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After the articles have been moved across the upper run of the conveyor 4 and most of the adhering moisture has been removed from the surface of the produce by the wiping units, the tray sections 9 are passed around the sprocket 8, being guided by means of guides until the sections reach the lower run of the conveyor. In the passage of the sections 9 along the upper run of the endless conveyor, they are pulled by means of the chain 98 until the sections pass around the sprocket 8, at which point the sections dump the produce onto the lower run of the conveyor. During the travel across the lower run of the conveyor, the sections 9 are pushed toward the entrance end of the conveyor. The produce is then discharged onto a chute 29 at the level of the lower run of the conveyor. By discharging the produce in this manner, it is discharged about eighteen inches higher in elevation than is ordinarily the case, particularly where multiple travel is employed, since considerable elevating is usually required to elevate the produce up to the entrance point. After the produce is discharged from the apparatus it is generally raised to about three feet from the floor in order to be passed to the inspection table and into bagging devices. By saving substantially eighteen inches at the discharge end of the apparatus, the produce has to be elevated less in order to reach the heighth for inspection.

During the passage of the produce or articles across the lower run of the conveyor 4, the moisture remaining on the surface of the articles may be removed by means of a draft of air passed from a fan or blower II over a fire box I3 or other suitable heating unit for heating the air. The air is preferably discharged onto the lower run of the conveyor through louvres I5, the position of which may be regulated so as to control the amount of air passing over the produce or articles in the final drying step.

The heating of the air from the blower I I during its passage over or through the heating unit may be controlled in any suitable manner to provide the optimum temperature for the drying of the produce or other articles to be dried.

The wiping units or mops 4D, after passing over the surface of the articles are preferably washed and dried in a cycle of operations so as to return them into contact with the articles after being properly dried, the mops or wiping units being initially passed into contact with the articles at the right of the chamber 2, at which point most of the water or surface moisture has already been removed from the produce or articles treated.

In order to cleanse and suitably dry the mops 40 after they have been passed over the articles, they are first passed over a sump 60 above the entrance end of the chamber 2, where they are washed by means of a spray of water from a spray 58 which removes adhering dirt or foreign matter from the wiping units, which are then passed through suitable wringer rolls 68 and 10 which serve to squeeze most of the excess water from the wiping units.

One of the wringer rolls, as 68, is preferably provided with a small fiat section 69, the said rolls being mounted and geared for operation so that the flat section 69 is turned so as to be adjacent the surface of the other wringer roll Ill as the rod portion 43 of a wiping unit passes between the wringers, thus assuring passage of the rods 43 between the wringer rolls without damage to the wringers or to the wiping units.

QU! lull From' the wringers 68 and 10, the mop units 4I are carried by a chain 38 over the sprocket 44, from which the wiping units are passed into a delayed action drying chamber 2| by means of a suitable conveying mechanism or rack. In order to disconnect the drying units 40 from the chain 38, a. mop-rod transferring device 3l is provided, which may be associated with or connected to the sprocket 44 and revolved thereby pushing the wiping units 40 out of the notches 45' in the chains 38 and for forcing the same in or on the inclined rack or conveyor mechanism 31, so that the rollers 49 pass into the space between the inclined tracks and 92 thereof. The tracks 90 and 92 which constitute in effect a holding means for the wiping units are preferably downwardly inclined so that the wiping units which are suspended from the' rods 43' move downwardly over the track 90 by means of gravity through the delayed action mop-drying chamber 2 I.

The rod transferring device 3l is preferably connected with the sprocket 44 so as to operate therewith, the sprocket having a pitch-circle circumference of a length equal to that of the distance between centers of the adjacent wiping unit rods 43 on vthe chain 38, so that the free end of the transfer device will come into contact with the rods at the proper time intervals for forcing the same from the chains 38. If desired, the device 3I may be separately mounted and operated independently of the sprocket 44, so as to remove the rods 43 and the wiping units attached thereto one by one from the chains 38 at the required intervals as they reach the position at the upper side of the sprocket from which they may be passed onto the conveyor mechanism 3l.

In the delayed action drying chamber 2|, the mops or wiping units 40 are brought more closely together or substantially into lateral contact and are subjected to a relatively high degree of heat for drying the units.

In order to rapidly dry the mops or wiping units in the drying chamber 2| to the desired condition of dryness at which the strands of the wiping units still retain a small proportion of water so that the capillary action remains high, or substantially at a maximum, air, which is preferably pre-heated. may be passed by means of a blower Il through louvres I9 into the delayed action drying chamber 2I, the louvres I9 being preferably adjustable in position so that the passage of air through the chamber 2| may be controlled as desired.

After the mops or drying units 40 have passed across the space in the mop drying chamber 2| and have been dried by the passage of air between the strands of the drying units, they are picked up from the rack or conveyor 31 by a moplifting device 33 similar to the means 3| above described. and are deposited one by one in the sockets 45' (Fig. 8) in the link members of the chain 38, the rollers 49 being then held in position adjacent the track member 5I. The mop units are then passed over the produce on the upper run of the conveyor 4 in the manner above described and the cycle of operations is repeated indefinitely, thus serving to continuously dry the produce as it passes through the drying apparatus in the manner described.

In connection with the furnace or flre box I3 is a heat exchanger as shown in Figs. 1, 2 and 3 by which air from the blower II may be heated to the desired degree before passing upwardly into the chamber 2|. A portion of the air from HUUIII the blower II passes through the louvres I5 below the lower run of the conveyor 4 for removal of surface moisture from the produce in its passage across the lower run of the conveyor and prevents excessive heating of the produce on the conveyor.

'Ihe air which passes into the space in the heat exchanger 25 around the flue 21 is heated in its passage outwardly and is discharged through an opening 23 above the upper surface of the ue 21 immediately below the mop-drying chamber 2| so that the heated air passes into contact with the mops at the left portion of the drying chamber 2|. It will be understood that a similar arrangement may be used at the right of the apparatus as shown in Fig. 2 so as to discharge air simultaneously above the upper surface of the flue 21, thus providing a symmetrically arranged heat exchanger by which air is discharged from both sides of the apparatus into the chamber 2 I. At the right of the chamber 2| air from the blower I1 passes through the louvres I9 into contact with the mops at the extreme right of the chamber 2| so as to cool the mops or drying units before they have passed into contact with the produce on the conveyor 4.

The air in the chamber 2| which has contacted with the mops or wiping units therein is very hot and contains a high percentage of moisture. 'Ihis air may be exhausted from the top of the apparatus to the left as shown in Fig. 1 into a stack 96 and does not contact with the produce in its passage through the apparatus.

It will be noted that the drying chamber 2| is separated from the produce handling portion of the drying apparatus by the upper part of the heat exchanger 25 and by a portion of the flue 21 as is apparent from Figs. 1, 2 and 3 of the drawings, and also by means of the hood 6I from the washing pan or sump 60 up to the wringers $8 and 10, and by means of an air baille 92 extending downwardly from under the blower I1.

It will be understood that because of the large opening for the discharge of air from the apparatus, there is little or no air drawn back from the mop drying chamber 2| to the main produce drying portion of the apparatus.

It may be stated that in the operation of the drying apparatus, a temperature of about 140 to 150 F. may be maintained in the producedrying section of the chamber 2, whereas a temperature of about 200 F. may be maintained in the mop drying chamber 2| at the wringer end of the chamber and a slightly lower temperature at the outlet side of the chamber adjacent the sprocket 50.

The blower I I will blow directly on the re box of the heating unit and discharges heated air both through the louvres I5 under the bottom run of the conveyor and through an opening 23 which is the outlet from the heat exchanger casing 25 around the pipe or conduit 21 leading to the smoke stack from the furnace.

The size and spacing of the openings through the louvres I5 over the re box I3 to the conveyor section may be regulated so as to balance the amount of air which goes into the upper section and into the lower section of the apparatus. An outlet 35 is connected to the pipe or conduit 21 which leads to a chimney or stack.

The blower I1 is preferably larger than the blower II. A portion o1 the air from the blower I I may go into the mop-drying chamber 2| after passage through the produce-drying section of the apparatus and is discharged with air from the chamber 2| through the stack 98.

The air from the blower I 1 may be at substantially the temperature of that of the producedrying section, but becomes heated by air from the re box I3 which passes through the opening 23 into the space below the chamber 2|. It will be obvious to those skilled in the art that separate heating means may be used, if desired, for heating the air from the blower I1 before it passes through thelouvres I9, and that the air supplied by the blowers I I and I1 may be proportioned or regulated in any desired manner so as to control the operation of the apparatus to obtain the desired drying eil'ect on the produce and to control the temperature of the produce, as well as the temperatures and speed of drying in the mop-drying chamber 2 I.

While the delayed-action mop-drying chamber has been shown and described as only partially separated from the remaining portion of the produce-drying apparatus, it is apparent that the drying chamber 2| may be substantially completely separated from the remainder of the apparatus by enclosing the chamber 2| within separate surrounding walls, so as to permit more complete control of the drying operation of the wiping units within the delayed-action drying chamber.

The details of construction and operation may be explained more in detail in connection with a modified form of the apparatus shown in Fig. 4 in which produce is passed across the chamber a plurality of times and passes from one conveyor belt to another in a series until it is discharged in dried condition from the apparatus. In the modified form of the invention, the numeral 2' designates a suitable casing or chamber of any suitable dimensions in which the drying operation may be carried out. Within the casing 2 is a produce-carrying conveyor 4 which is preferably mounted on sprockets 6' and 8' which may be rotated in a clockwise direction, for example, so that the upper surface of the conveyor moves toward the right, as indicated by the arrow in Fig. 4 of the drawings. Any desired number of produce-carrying conveyors may be used, as may be desired, although in the modified form of the apparatus shown, three such conveyors are used, as illustrated in the drawings. The second conveyor belt I0 is preferably mounted below the conveyor belt 4' and is supported on and passes over sprockets I2' and I4' which may be rotated in a counter-clockwise direction S0 as to produce movement of the upper surface of the belt I0 toward the left, as indicated by the arrow adjacent the conveyor belt III'. Mounted below the conveyor belt I0 is a conveyor belt I6', which is preferably supported on sprockets I 8 and 20' which may be rotated in a clockwise direction, so that the upper surface of the belt moves toward the right as indicated by the arrow adjacent the upper run of the conveyor IB'.

The produce to be dried may be suitably fed through an inlet; opening 22 at the upper left portion of the chamber 2', so that the produce is passed onto the surface of the belt 4 at a controlled rate, the material being then conveyed through the chamber to the extreme right of the belt, after which it passes over the end portion thereof on the sprocket 8 and falls onto a guide plate 24', by which it is directed onto the extreme right end of the conveyor I0', by which it is then transported across the chamber 2' and CONTACT Wl h' SUUDS.

over the extreme left portion of the conveyor I', from which it is dropped onto the guide plate 26', which serves to feed the produce onto the upper surface of the conveyor belt; I6' at the extreme left portion thereof, by which it is again conveyed through the chamber 2' and after passing over the extreme right end of the conveyor belt I6', it is dropped into the rotary air lock outlet 28' from which it may be discharged from the apparatus without substantial admission of air. The produce when expelled by the air lock outlet is dumped onto a conveyor belt 30', by which the produce may be transported to storage or immediately packed, if desired.

In order to remove the remaining moisture from the produce, after the preliminary moisture-removing operation by the action of the mops or wiping devices, to be hereinafter described, heated air is admitted into the chamber 2' through an air inlet 32', which as shown in the drawings is preferably located adjacent to the outlet 28' for the produce. The air which is admitted passes first over the upper surface of the conveyor belt I6' into contact with the produce in a direction to the left in the drawings, the air path being confined by a lower partition 34', positioned below the upper surface of the conveyor belt I6', and by an upper partition 36', positioned below the upper surface of the conveyor belt IU'. Both of these partitions extend preferably the full width of the chamber 2' and are preferably of a length corresponding substantially to the distance between the adjacent sprockets between which they extend. The air, after passing over the surface of the produce on the conveyor I6. passes around the left end of the conveyor l0' and over the surface of the conveyor l0' toward the right so as to remove additional moisture from the surface of the produce. The air then passes through the space between the guide plate 24 and the right end of the conveyor belt 4', and into the upper right hand portoin of the chamber 2 in which it is employed to eiect the drying of the mops or wiping units, as will hereinafter be described.

In the upper portion of the chamber 2 is a main link belt for controlling the passage of the wiping units, the link belt comprising spaced parallel chain members 38' and 39' (Figs. 5 and 9) by which the mops or wiping units 40' are moved over the surface of the conveyor 4' in a direction opposite to that of the movement of the belt so as to come into wiping contactl with the produce on the surface of the conveyor 4'. The mops, towels or wiping units 40' are preferably carried on rods 43' which are held in place by notches 45' in the links, as 41', in the chains 38' and 3B'. The mop rods 43' are supported by a wheel or roller 49' on each end of the rods, the rollers being in turn supported on guide tracks as shown. The mops or wiping members are mounted at regular intervals along the chains 38' and 39', so that when the wiping members are stretched taut along the conveyor chains, they will substantially span the distance to the next towel or wiping member on the chain without overlapping.

The chain members 38' and 39' are preferably mounted on sprockets 53', 4|', 42', 44', 46', 48', 50' and 52', so that the chain members or link belt may be continuously moved through the path as shown to carry out the desired cycle of operations. It will be noted that the sprockets 46' and 48' are positioned considerably below the sprockets 44' and 50', serving thereby to sub- UUHI MII stantially lengthen the path of movement in which the chain members 38' and 39' move in passing from the sprocket 44' to the sprocket 50. The chains 38 and 39 of Fig. 1 and the chains 38 and 39' of Fig. 4 are termed cyclic means for continuously dragging the wiping units over the produce which is carried beneath the wiping units.

The guide tracks 5|' are mounted below or on the outside of the chain members 38 and 39 so as to control the movements of the mops of wiping units 40' in the passage over the produce while carried by the chains 38' and 39. In the passage of the mops over the surface of the produce, the moisture from the produce is progressively withdrawn or soaked up, so that by the time that a unit 40' passes out of contact with the produce the mop or wiping unit is substantially saturated with moisture and contains also a considerable amount of dirt or foreign matter which has been removed from the surface of the produce.

In order to cleanse the mops or wiping units before drying the same, they are passed under a spray washer 58' so as to thoroughly cleanse the wiping units, which may be held in place under the spray by means of a screen or perforated baffle member 66' during the spraying operation. The water and dirt or foreign matter from the mops or wping units is collected in a sump 60', from which it may be removed or drained off by means of a pipe 62. In order to confine the spray to the surface of the mop or wiping unit during the washing operation, a hood 64' may be provided around the spray member, substantially as indicated in the drawings.

After the mops or wiping units have been thoroughly cleansed in the manner described, they are preferably passed between wringer rolls 68' and 10', which rolls are preferably rubber cored and of the same diameter as the pitch of the sprocket member 42'. By this means, a. considerable proportion of the water or moisture in the wiping unit is removed and passes into the sump 60' to be removed or drained with the remaining water therein.

After removal of the portion of the water from the wiping units by means of the wringer rolls, the units are preferably passed over a series of heating units, as steam heated pipes, for example, which serve to raise the temperature of the water remaining in the mops or wiping units to such an extent as to cause evaporation of an additional amount of water therefrom, leaving however an amount of moisture in the strands or fabric so as to retain after further drying, a maximum amount of capillary action, whereby the units may operate immediately after the further drying operation in drying chamber 2|' with an initial high absorbing capacity for the removal of surface moisture from the produce treated. Subsequent to the heating action k" passage of the wiping units over the heating elements 1I', they are subjected to a delayed drying action in a portion of the chamber 2|' which is substantially separated from the remaining portion of the chamber, air of high absorption capacity being passed into contact with and through the strands or meshes of the wiping units. For this purpose the wiping units are disengaged from the chain members 38', 39 and are passed onto slower moving chains 12', 13' in which the mop units are positioned proportionately nearer together. The chain members 12', 13 are mounted on sprockets 15', 11 and are operated l IUUUI in a clockwise direction so that the mop units or wiping units mounted thereon pass across the distance between the sprockets in the same time that the corresponding 'point on the chains 38', 39', such as the notch 45' from which the wiping unit was removed, passes over the elongated path from the top of the sprockets 44' around the sprockets 46', over sprockets 48' and back to the top of the sprockets 50'. The chains 12' and 13 provide holding means for the rods 43' and likewise the wiping units as they pass through the drying chamber.

'I'he drive for the chain members 38', 39' is preferably through a drive shaft 54', as indicated in Fig. 6 of the drawings, although the driving action may obviously be accomplished at any other suitable point in the mechanism. The drive for the chain mem-bers 12', 13' may be independent of the drive for the chain members 38', 39', as fby means of a drive shaft 89' to which the sprocket 11' is keyed, but it is ypreferable to have the chain members 38', 39' and 12', 13' interdependently operated, as -by means of interconnecting gearing, by which the corresponding slots or notches which engage the mop rods may be positively brought into lateral registration at the time of transferring the wiping units from one link mechanism to the other, as above described.

It will be understood that the path of detour, or the portion of the path of the chains 38', 39' which is offset from the main path, may be proportioned to the horizontal distance or direct path between the sprockets 15' and 11' so that any desired concentrating or crowding effect of the mop units may be obtained to provide the desired delayed drying action.

Any suitable means may be employed for transferring the wiping units, including the mop rods 43' and the associated guide wheels 49', from the chain members 38', 39' to the auxiliary chain conveyors 12', 13', although the preferred form of mechanism is a plurality of spaced cam members 19', which may be keyed to the shaft 8|' on which the sprocket members 15' are mounted, thereby revolving at the same speed as the sprockets 15'. A raised portion on each cam member 19' serves to raise the mop rod 43 out of the notch 45' in the link belts 38' and 38' and to carry the wiping unit at a reduced rate f speed when transferred to the notch or depression in the raised portion of the cam member, the unit being carried in the notch until'in the rotation of the cam member, the unit is again dropped into a corresponding notch or notches 81' (see Fig. in the link belts 12 and 13'. These cam members 19 are so arranged on the shaft 8|' that they will remove the Wipers in timed relation with respect to the differential speeds of the chains 38', 39 and 12', 13.

Instead of the means, above described for transferring the wiping units from the chain belts 38', 39' to the chain conveyors 12', 13', other suitable means may be used, as for example, raised portions on the tracks 5l' may be used to lift the wheels 49' and the units at the desired points of transfer from the rapidly moving belt to the shorter slowly moving conveyor belt. The raised portions on the tracks may be sloped so that as soon as the wheels 49' of the wiping units have passed beyond the sprockets 44', and the mop rods have moved out of contact with the notches 45' of the link belts, the wiping units will be lowered again and thereafter will be retained in the notches 81' in the link belts 12', 13'. In order to assure controlled positive action in the forward movement of the wiping units at the time of transfer from the notches 45' to the notches or recesses 81', a pusher cam member may be employed, which may be connected to the sprockets 15' or mounted on the same shaft so as to provide forward movement at the desired rate of speed for obtaining proper seating action in the recesses to which the unit is transferred.

The air which has been admitted to the chamber 2' for providing the final drying action of the produce, by passing the heated air progressively over the advancing produce on the conveyor belts I0' and I6' in counter-current relation to movement of the produce, and has become moist or of relatively higher humidity, although still able to take up comparatively large amounts of water, passes upwardly into the right upper portion of the chamber 2', and from thence it passes into the space above the chain members 12', 13', where it is prevented from passing into the forward part of the chamber by means of the baille plate 14'. The moist air then passes from the upper part of the chamber downwardly between the strands of the mops or towel portions of the wiping units, so as to cause progressive drying thereof in the forward movement over the shunted path.

It will be understood that mop units adjacent to the sprocket 50 receive the larger proportion of air, so that greater drying action takes place as the wiping units move forwardly. By further heating the air after it has been used in removing the remaining moisture from the partially dried produce, as by means of a heat-exchanger, for example, the drying of the wiping units may be controlled so that they become relatively dry, but still contain a. sulcient amount of moisture so that when brought into contact with a wet surface, such as wet produce, they will absorb or take up moisture therefrom almost immediately, and do not have to become further wetted in order to increase the capillary action for this purpose.

After the wiping units reach the sprocket 50 in their travel across the chain belts 12', 13', they are then transferred in their proper relative positions back to the chain members 38', 39' so as to continue in the cycle of operations as above described.

Due to the fact that the movement of the chain members 38', 39' is more rapid than that of the chains 12', 13', the wiping units are preferably moved out of contact with the slower moving chains by means of cam action similar to that above described in connection with the reverse transferring movement. The cam action becomes operative preferably when the wiping units reach the sprockets 11', and the cam device carries the units 1n a recess or notch so that the mop rods are out `of contact with the sprockets 11' until the units have been carried below the level of the shaft member 88', after which the cam member lowers the unit onto the chains 38', 39 in the proper notches 45', and the units are then carried progressively through the cycle as above explained.

In order to control the passage of air in passing upwardly in the chamber 2' into the space about the conveyors 12' and 13', a baille plate 18 is preferably suspended in the chamber 2 just beyond the mop-drying compartment or section so as to direct the now of the incoming air to the upper part of the drying chamber. At the lower Uil l im; y che uw v v CONlACl Wl H SUUDS.

UUHI UH end of the baiile member is suspended a mop or towel 'I8' extending the full width of the baille member to prevent the ow of air laterally from the desired path. The length of the towels or mops is preferably such as to come into contact with the produce as it passes over the end of the conveyor belt 4. After the air has passed through and between the mop strands or towels suspended on the chain members 12', 13', it is preferably passed in a path around the sump S' and passes out of the chamber 2 through the passageway 22', or it may be expelled out of the chamber 2' by means of a separate outlet if desired.

It will be understood that various changes or modifications may be made in the device as described, and as shown in the drawings, without departing from the spirit or scope of the invention as defined in the annexed claims.

Having thus described the invention, what is claimed as new is:

1. A n article-drying apparatus comprising a main chamber, an endless conveyor within said chamber for passing articles to be dried therethrough, means for operating the said conveyor, a series of wiping units, cyclic means for continuously passing the series of wiping units at a uniform rate of travel over the upper run of the said conveyor in a direction of travel opposite to that of the said upper run, a wiping-unit drying section within said main chamber, means for passing the said wiping units through said drying section at a rate of travel slower than said uniform rate of travel, means for transferring the wiping units to the last-mentioned means, and means for synchronizing the movement of the wiping units through said drying section with said cyclic means, and to return said wiping units to said cyclic means with continuous feed.

2. An article-drying apparatus comprising a main chamber, an endless conveyor within said chamber extending longitudinally therethrough for passing articles to be dried through the chamber, means for operating said endless conveyor at a uniform rate of speed, a series of wiping units, conveyor means for passing the series of wiping units over the upper run of the said endless conveyor, means for detachably fastening the said wiping units to the said conveyor means, a wiping unit drying section within said main chamber, holding means for said wiping units within said drying section, means for transferring said wiping unit from said conveyor means to said holding means and means for retransferring the said wiping units from said holding means to said conveyor means.

3. An article-drying apparatus comprising a main chamber, an endless conveyor within said chamber for passing articles to be dried through the chamber, means for moving said endless conveyor at a uniform rate of speed, a series of wiping units, cyclic means for passing the series of wiping units at spaced intervals over the upper run of the said endless conveyor in a direction counter-current to that of the said endless conveyor, means for passing air into contact with articles on said endless conveyor for the drying of the articles, a wiping-unit drying section in the portion of the main chamber above the upper run of said endless conveyor, means for passing heated air through said drying section, means for receiving and for passing said wiping units through said drying section, means for transferring the wiping units from the cyclic means to the receiving means, said receiving means having a restricted capacity for the wiping units so that said wiping units are crowded together during passage thereof through said drying section and means for returning said wiping units to the cyclic means in said spaced interval arrangement for passage thereof over the said upper run of the endless conveyor.

4. An article-drying apparatus comprising a main chamber, an endless conveyor within said main chamber extending longitudinally therethrough for passing articles to be dried through the chamber, means for operating the said endless conveyor at a predetermined uniform rate of speed, means for feeding articles to be dried onto one end of said conveyor, means for passing heated air into contact' with the said articles during passage thereof through said chamber while supported on said conveyor, a series of wiping units, conveyor means for passing said wiping units in spaced relation into contact with articles on the upper run of said endless conveyor, a wiping unit drying chamber within said main chamber, means for passing heated air through said drying chamber, means for withdrawing said wiping units from said conveyor means to pass the said wiping'units into said drying chamber, means for passing the said wiping units through said drying chamber in more closely spaced relation at a reduced speed of travel, means for withdrawing the said wiping units from said drying chamber and returning the same onto said conveyor means in said spaced relation, and means for withdrawing the dried articles from said main chamber.

5. An article-drying apparatus comprising a main chamber, an endless conveyor within said chamber for passing articles to be dried therethrough, means for operating the said conveyor at a uniform rate of speed, a series of wiping units, cyclic means for continuously passing the series of wiping units at a uniform rate of travel over the upper run of the said conveyor in a direction of travel opposite to that of the said upper run, means for spraying water onto the wiping units after passage thereof into contact with said articles, a wringer for removing excess water from said wiping units, a wiping-unit drying section within said chamber, means for passing heated air through said drying section, means for passing the said wiping units through said drying section at a rate of travel slower than said uniform rate of travel, means for transferring the wiping units to the last mentioned means, means for synchronizing the movement of the wiping units through said drying section with said cyclic means and to return said wiping units to said cyclic means with continuous feed, and means for returning the wiping units successively to the cyclic means.

6. An article-drying apparatus comprising a main chamber, an endless conveyor within said chariber for passing articles to be dried through the chamber, means for moving said endless conveyi at a uniform rate of speed, a series of wiping units, cyclic means for passing the series of wiping units at spaced intervals over the upper run of the said endless conveyor in a direction counter-current to that of the said endless conveyor, means for passing air into contact with articles on said endless conveyor for the drying of the articles, a wiping-unit drying section in the portion of the main chamber above the upper run of said endless conveyor, means for passing heated air through said drying section, means for receiving and for passing said wiping units HUUIII through said drying section, said receiving means being of short length so that said wiping units will be crowded together during passage thereof through said drying section, means for transferring the wiping units from the cyclic means to the receiving means, means for returning said wiping units to said cyclic means in said spaced interval arrangement for passage thereof over the said upper run of the endless conveyor, and means for controlling the flow of said air and heated air to effect drying of the said wiping units in the passage through the drying chamber while the desired amount of moisture is removed from the said wiping units to provide substantially the maximum capillary action in said units for the removal of moisture from the said articles.

7. An article-drying apparatus comprising a main chamber, an endless conveyor within said chamber extending longitudinally therethrough for passing articles to be dried through the chamber, means for operating said endless conveyor at a uniform rate of speed, a series of wiping units, conveyor means for passing the series of wiping units over the upper run of the said endless conveyor, means for detachably fastening the said wiping units to the said conveyor means, means for passing heated air over the articles on said endless conveyor, a wiping unit drying section within said main chamber, a heat exchanger, means for passing air through said heat exchanger and into said drying section, holding means for said wiping units within said drying section, means for transferring said wiping units from said conveyor means to said holding means at the entrance end of said drying section, and means for re-transferring the said wiping units from said holding means to said conveyor means at the exit end of said drying section.

8. An article-drying apparatus comprising a main chamber, an endless conveyor within said main chamber extending longitudinally therethrough for holding articles to be dried, means for operating the said endless conveyor at a predetermined uniform rate of speed, means for feeding articles to be dried onto one end of said endless conveyor, means for passing heated air into contact with said articles during passage thereof through the chamber while supported on said endless conveyor, a series of wiping umts, conveyor means having notched link members for holding said wiping units in spaced relation thereon, said wiping units being passed over the articles on the upper run of said endless conveyor in a direction opposite to the direction of movement of said endless conveyor, a wipingunit drying chamber within said main chamber, a heat exchanger, means for passing air through said heat exchanger into said drying chamber, a. downwardly inclined track ln said drying chamber for supporting wiping units during passage through the drying chamber, a device for withdrawing said wiping units from said notched link members of the conveyor means and transferring the same onto said track for passage through the drying chamber by gravity feed, a lifting device at the exit end of said drying chamber for removing the said wiping units one by one from said track and returning the same into said notches of the link members of the conveyor means and means for withdrawing the dried articles from said main chamber.

BROADUS WILSON. 

